In a recent article for Slate.com, Eric Posner argues for First Amendment restrictions, due to the threat of ISIS propagandizing. Posner writes:

Consider a law that makes it a crime to access websites that glorify, express support for, or provide encouragement for ISIS or support recruitment by ISIS; to distribute links to those websites or videos, images, or text taken from those websites; or to encourage people to access such websites by supplying them with links or instructions.

It can hardly be denied that Eric Posner is not only among the best scholars in Law and Economics working today—he is a top legal scholar tout court, regularly topping lists of most-cited legal academics. It is therefore with the utmost respect and admiration that I write that his proposal is, from a historical perspective, totally misguided.

As an ironclad principle, not only in the laws of the United States, but also the laws of civilizations over the centuries, and also in the internal policies of private entities, restraints on speech invariably appear moronic in the bright light of day. I do not use the term "moronic" lightly here.

A brief tour of the history of restrictions on speech will illustrate the point:

The execution of Socrates for "corrupting the youth" of Athens with his philosophy.

The Catholic Church's banning of "corrupting" literature, including the writings of (note that unless otherwise noted, these bans were in effect until the abolishment of the Index Liborum Prohibitorum in 1966):

Galileo Galilei, Nicolas Copernicus, and Johannes Kepler's scientific writings (until the comically late year of 1835, when the Church finally gave up its opposition to heliocentrism)

Rene Descartes

Hugo Grotius

Blaise Pascal

John Calvin

Baruch Spinoza

John Locke

John Milton

Bishop Berkeley

Daniel Defoe

Voltaire

Denis Diderot

David Hume

Jean-Jacques Rousseau

Nicholas de Condorcet

Immanuel Kant

Jeremy Bentham

John Stuart Mill

The fatwa against Salman Rushdie and the publishers of The Satanic Verses.

"Seditious libel" laws in the English common law, which hold that "criticism of the Queen," "criticism of the government," or "promoting discontent" are criminal offenses (notably, proving the truth of one's utterances is not an exculpatory defense).

It seems absolutely clear that each of these cases, viewed through the sober light of history, reveals the concerns of policymakers to be utterly absurd and paranoid. The justification, for example, for restraints on lunatic socialists distributing pamphlets, that their soapbox rants would somehow undermine the American war effort, or usher in an era of communist totalitarianism must today seem absurd. As absurd as the lunatics in the park today calling for investigations into the Kennedy Assassination and UFO sightings posing a threat to national security.

Of course, Posner is aware that his proposed law would run into a problem with the Constitution, but he nevertheless seems to think something along those lines is justified by circumstances, and that perhaps First Amendment jurisprudence needs to be rethought in light of the threat of Islamic fundamentalism in the internet age. This, no doubt, is no more than the same paranoid overreaction that caused the British and French to ban Nabokov's Lolita. In every age, people invariably think the circumstances they face unique, and that the "threats" they face are unlike any previously encountered in history. These "threats" are then taken as justification for restrictions on freedom of thought, speech, and the related right to receive information.

What really is the threat of ISIS propaganda on the internet? Posner claims the danger is "serious," because it can (and arguably has) resulted in some mass shootings. Yet let us think proportionally about the cost of several dozens of deaths per year due to ISIS-influenced terrorist acts inside the United States. In a nation of more than 300 million, does it make sense to alter our conception of a core constitutional principle, in order to prevent a handful of deaths—however tragic they may be?

If the purpose of terrorism is to induce an overreaction, and thereby to create a multiplier effect, then it seems that any response that requires us to change what ordinary people are allowed to do should be counted as a "win" in the terrorists' column.

Finally, Posner seems not to consider the risk of blowback effects, which seem to me quite serious. Though I haven't any data on the phenomenon, I suspect that a large number of people drawn to ISIS are not, as Posner intimates, casually browsing the internet when they click the wrong link, sending them down the rabbithole of "jihadification." Rather, it seems to me that those most likely to find ISIS's message appealing are disaffected young people, who actively seek out a way of rebelling. Imposing criminal prohibitions (especially criminal prohibitions with very low probabilities of apprehension) merely create an aura of taboo, of elicitness, which will only make it more appealing for its target audience. In the same way that stodgy government campaigns against drug use made it "sexy" for a large number of young people, it seems to me likely that a prohibition against the consumption of ISIS propaganda will only encourage those most likely to be influenced by it to seek it out.